Electromagnetic electrolyte pump



1964 H. F. POPPENDIEK 3,160,100

ELECTROMAGNETIC ELECTROLYTE PUMP Filed Nov. 20, 1961 3 Sheets-Sheet 1 Jim Fig. I I4 w INVENTOR.

HEINZ F. POP PENDIEK BY mamw Fig.2

1964 H F. POPPENDl-EK ,160,1

ELECTROMAGNETIC ELECTRQLYTE PUMP Filed Nov. 20 196-1 3 Sheets-Sheet 2 VOLTAGE SQU'RJC E INVENTOR.

HEINZ F. POPPENDIEK Dec. 8, 1964- H. F.. POPPENDIEK 3,150,100

ELECTROMAGNETIC ELECTROLYTE PUMP Filed Nov. 20,. 1961 3 Sheets-Sheet 3 voLrAeia: so-uRcE Fig. 5

INVENTOR.

HE! NZ F. POPPE NDIEK BY Jamsxm United States Patent Ofiice 3,169,139 ELEUTROMAGNETFC ELECTRGLYTE PUMP Heinz F. Foppendiek, 8636 Dunaway Drive, La Jolla, Qallf. Filed Nov. El), 1961, Ser. No. 153,316 3 Claims. (Cl. 163-1) This invention relates to pumps, and more particularly to pumps for causing the movement of fluids that have only limited electrical conductivity.

Background It is frequently necessary or desirable to pump liquids that are corrosive, that should not be violently buffeted, that tend to seep through extremely small cracks or openings, or that should be kept completely enclosed to avoid contaminating them.

In cases of the above type, the usual mechanical pumps are unsatisfactory because of their requirements for moving blades or vanes. These in turn impose limitations as to the types of materials to be used, which usually should not be subject to corrosion, and the need for seals, which ordinarily must not leak or permit the entrance of air.

The above considerations have lead to the development of the so-called electromagnetic pump. This pump solves most of the above diihculties when used to pump electrically conductive liquids such as mercury, sodium, or the like, or slurries having good electrical conduction properties.

However, there are many cases where it is necessary to pump liquids that are only slightly or partly electrically conductive; these materials including acids, alkalies, blood, and the like, while still preventing leakage and contamination.

Objects and Drawings It is, therefore, the principal object of my invention to provide an improved pump.

it is another object of my invention to provide an improved pump for partly conductive fluids.

it is a further object of my invention to provide an improved pump for partly conductive materials that may be corrosive, or may be easily contaminated.

It is a further object of my invention to pump the above materials without unduly buifeting or heating them.

The attainment of these objects and others will be realized from the following specification, taken in conjunction With the drawings, of which:

FIGURE 1 is a perspective View of a prior art elec tromagnetic pump;

FIGURE 2 is a perspective view, partly cut away, of my P p;

FEGURE 3 is a transverse sectional view taken along line 3-3 of FIGURE 2 with the electrical circuitry of the pump shown diagramatically;

FIGURE 4 is a sectional view taken along line 4- i of FIGURE 3 and rotated 90 degrees; and FIGURE 5 is a sectional View, similar to FIGURE 3, of the pump with coolant flow parallel to the pumped fluid.

Brief Description of the Invention Broadly stated, my invention contemplates an electromagnetic pump designed to cause the movement of partly conductive fluids. As such, the fluid is caused to flow through a plurality of parallel passageways, the walls of which act as the electrodes that apply an electric current to the fluid. The passageways are tall and thin, I

of heat and my pump contemplates a cooling arrangement incorporated as an integral part thereof.

Detailed Description of the Invention The operation of my invention will be more clearly understood after a study of the prior-art electromagnetic pump of FIGURE 1. Pump 10 operates in accordance with the motor principle, which states that if a conductor is positioned in a magnetic field and simultaneously has a current flowing through it, the conductor will be urged to move. In FIGURE 1 a tube 12 contains a conductive liquid such as mercury, which is to be pumped or moved along within the tube. Magnets 14 produce a magnetic field oriented as shown by arrows 16, while current flows through the mercury as shown by arrows 18, electrodes 24 and 22 being used to conduct the current to and from the fluid.

The mercury, in this case is the conductor, and is urged to move through the tube 12 in the direction indicated by arrows 24.

Due to various considerations, it becomes necessary that the pole pieces 14 be as close to each other as possible; and this dictates the use of a flattened tube 12. Still other factors make it desirable to use a direct current, and a permanent magnet.

As previously indicated, my pump causes the movement of partly conductive fluids, which shall for convenience be called electrolytes. Since these fluids are not good conductors of electricity, as was the fluid for which the pump of FIGURE 1 was designed, that pump is unsatisfactory for pumping electrolytes.

This follows for several reasons. Firstly, the conductivity of tube 12 is so much better than that of the electrolyte, that the electric current would tend to flow through the tube rather than through the electrolyte. Secondly, the distance between the electrodes is so large that the thickness of the electrolyte between the electrodes would deter the flow of electricity between the electrodes. Thirdly, for reasons to be discussed later in more detail, a direct current may be objectionable. And fourthly, appreciable heat is produced in pumping electrolytes; so that special cooling facilities must be pro- Vided.

With the foregoing discussion in mind, my invention will be understood from a study of FIGURE 2, which is a representation of my pump in perspective. In pump 25 the electrolyte flows through channels 2-3, four such channels being shown. As will be noted, channels 23 are tall and thin, in direct contradistinction to those of the prior-art pump, wherein the tube is short and fat.

Each channel 28 has side walls, 3lla and 3%, formed of electrically conductive material, so that they may serve as a pair of electrodes. While side walls 39 may be formed of any suitable material, such as a metal, conductive glass, or a conductive coating on an insulator, it is preferable that they be thin and have good heat conducting properties.

Since oppositely positioned side walls 3% and 30b are electrodes, they must be electrically insulated from each other. This is readily achieved by top and bottom walls 32 of an insulating sealing material such as rubber or plastic. Thus walls 36 and 32 form a leakproof channel of any desired length. The adjacent Walls of adjacent channels must also be spaced apart to avoid short circuits.

Electrolytes, as previously discussed, have a relatively high electrical resistance; so that a minimal thickness of electrolyte should be positioned between opposing side walls Talia and 3%. In order to provide appreciable volume of flow, channel 28 must therefore be relatively tall; and to accommodate an appreciable volume of flow,

' 3 several channels 28 are positioned in a side-by-side relation, but spaced-apart for reasons to be discussed later.

The electrolyte is also moved in accordance with the motor principle discussed in connection with the priorart pump, so a magnetic field is produced by magnets 34. Thus in pump 26, a conductor (the electrolyte) is in a magnetic field, and an electrical current is flowing through it due to the potentials applied to the side walls 30. The electrolyte is therefore urged to move along channels 28.

The electrolyte has a fairly high electrical resistance, so the thickness of fluid between sidewalls 30a and 3% produces a resistance having a finite value. When electricity flows through a material having a finite value of resistance, heat is produced; the amount of heat being given by the factor 1 R, where I is the electrical current flow and R is the resistance. The theoretical and experimental verification of the cooling process can be found in Forced-Convention Heat Transfer in Pipes with Volume-Heat Sources Within the Fluids, H. F. Poppendiek, Chem. Engr. Prog. Symp. Series, vol. 50, No. 11, 1954 and Heat Transfer in Heterogeneous Circulating-Fuel Reactors, H. F. Poppendiek and L. D. Palmer, Nuclear Sci. & Engr., vol. 3, No. 1, January 1958. In an electromagnetic pump, the elfectiveness increases as the electrical current increases, so the heat produced may be appreciable. Usually, the pumped fluid should not be heated, so my pump incorporates cooling means therein. Coolant enters the pump chamber through an inlet 36, circulates through passageways 37 around the various channels 28, and exits through outlet duct 38. The ends of coolant passageways 37 are closed by transverse walls 39 to prevent mixing of coolant with the electrolyte and said walls also serve to support the channels 28 and are thus of insulative material, as indicated in FIGURES 2 and 4. In the chamber, the coolant flows past walls 30a and 30b and 32, and in this way extracts heat from the pumped fluid. The walls of channels 28 are preferably thin and have good heat conducting characteristics to facilitate the cooling process. It is preferable that the relation between the walls and both the coolant and the fluid be such as to wet the walls, as this relation aids the cooling process.

The coolant may, of course, flow in any desired direction. FIGURES 2 and 3 illustrate transverse flow passageways with the entrance and exit ducts positioned at diagonally opposite corners. Alternatively, the ducts may be on the same side of the pump chamber. In some instances, it may be desired that the coolant flow parallel to the pumped fluid, and this may be achieved by suitable positioning of the inlet and outlet ducts, and the coolant passageways, as illustrated in FIGURE 5, the transverse walls supporting the channels 28 as before but not closing the passageways 37, allowing the coolant and electrolyte to flow parallel to each other in channels 28 and passageways 37.

Generally speaking, electrolytes have the characteristic that they break down when an electric current flows through them. This action tends to concentrate various materials at the electrodes. In some cases these materials are gases, while in other cases they may be undesirable compounds.

To avoid this breaking down, I prefer to have alternating current flowing through the electrolyte. I have found that a frequency of about 1,000 cycles per second is satisfactory, since it prevents breakdown, and yet permits the use of readily available electrical components.

Since the electric current flowing through the electrolyte reverses its direction 1,000 times per second, it is necessary that the magnetic field also reverse its direction in synchronism. This effect is readily achieved, as illustrated in FIGURE 3, by having a voltage source 40 supply the power for the electrodes and the magnetic field. Source 40 energizes a coil 42 that activates the magnets; so that the desired relation is obtained. In

ii this way breakdown of the electrolyte is prevented, and yet the fluid is always pumped in the same direction.

Summary It will be realized that my invention provides a means for pumping fluids that have a relatively low electrical conductivity. Moreover, the pumped fluids have an even movement and constant pressure. In addition, the fluid may be maintained at any desired temperature and pressure. Furthermore, there is no danger of the fluid leaking out, or air leaking in.

The above conditions are ideal for pumping blood, and well adapted for pumping electrolytes such as acids, bases, various oils, corrosive liquids, and the like.

It is understood that minor variations from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

I claim:

1. In combination with means for producing a magnetic field, a plurality of fluid-conducting channels of substantially rectangular cross section, each of said channels comprising a pair of electrically conductive side walls and a pair of insulative top and bottom walls, said side walls having a greater dimension than said other walls and being positioned parallel to said magnetic field;

means for applying a voltage between said pairs of side walls, whereby an electric current flows through the fluid in each said channel across the smaller dimension of said channel and transverse to said magnetic field;

a plurality of coolant passageways, certain of said passageways being positioned between adjacent said channels, said sidewalls of said channels defining the sidewalls of said passageways; and

means, comprising inlet and outlet ducts, for causing said coolant to flow through said passageways.

2. An electromagnetic electrolyte pump comprising:

means for producing a magnetic field;

a plurality of spaced-apart electrolyte conducting channels of substantially rectangular cross section, each of said channels comprising a pair of electric and heat conductive side walls and a pair of electrically insulartive top and bottom walls, said side walls having a larger dimension than said other walls, and being positioned parallel to said magnetic field;

means for applying a potential between each said pair of side walls, whereby an electric current flows through said electrolyte in each of said channels across the thickness of said electrolyte and transverse to said magnetic field, and said electrolyte is urged to flow through said channels;

a plurality of coolant passageways oriented perpendicularly to said channels, certain of said passageways being positioned between adjacent said channels, said sidewalls of said channels defining the side walls of said passageways, whereby said coolant extnacts heat from said electrolyte through said heat conducting side walls; and

means, comprising inlet and outlet ducts, for causing said coolant to: flow through said passageways.

3. An electromagnetic electrolyte pump comprising:

means for producing a magnetic field of reversible direction;

a plurality of spaced-apart electrolyte conducting channels of substantially rectangular cross section, each of said channels comprising a pair of electric and heat conductive side walls and a pair of electrically insulative top and bottom walls, said side walls having a larger transverse dimension than said other Walls, and being positioned with said transverse direction parallel to said magnetic field;

means for applying a potential between each said pair of side walls, whereby an electric current flows through said electrolyte in each said channel across the thickness of said electrolyte and transverse to said magnetic field, and said electrolyte is urged to flow through said channels;

a source of alternating power;

means for applying the alternating power from said source to said magnetic field producing means and to said potential applying means;

a plurality of coolant passageways oriented perpendicularly to said channels, certain of said passageways being positioned between adjacent channels, said sidewalls of said channels defining the side walls of said passageways, whereby said coolant extracts heat from said electrolyte through said heat conducting side Walls; and

means, comprising inlet and outlet ducts, for causing said coolant to flow through said passageways.

References Cited by the Examiner UNITED STATES PATENTS Beck 103--1 Lago 103-4 Vandenberg 103-1 Vandenberg 103-1 Werner 103--1 Szechtman 103l Cochran et a1 1031 Blake 103---1 FOREIGN PATENTS LAURENCE V. EFNER, Primary Examiner. 

1. IN COMBINATION WITH MEANS FOR PRODUCING A MAGNETIC FIELD, A PLURALITY OF FLUID-CONDUCTING CHANNELS OF SUBSTANTIALLY RECTANGULAR CROSS SECTION, EACH OF SAID CHANNELS COMPRISING A PAIR OF ELECTRICALLY CONDUCTIVE SIDE WALLS AND A PAIR OF INSULATIVE TOP AND BOTTOM WALLS, SAID SIDE WALLS HAVING A GREATER DIMENSION THAN SAID OTHER WALLS AND BEING POSITIONED PARALLEL TO SAID MAGNETIC FIELD; MEANS FOR APPLYING A VOLTAGE BETWEEN SAID PAIRS OF SIDE WALLS, WHEREBY AN ELECTRIC CURRENT FLOWS THROUGH THE FLUID IN EACH SAID CHANNEL ACROSS THE SMALLER DIMENSION OF SAID CHANNEL AND TRANSVERSE TO SAID MAGNETIC FIELD; A PLURALITY OF COOLANT PASSAGEWAYS, CERTAIN OF SAID PASSAGEWAYS BEING POSITIONED BETWEEN ADJACENT SAID CHANNELS, SAID SIDEWALLS OF SAID CHANNELS DEFINING THE SIDEWALLS OF SAID PASSAGEWAYS; AND MEANS, COMPRISING INLET AND OUTLET DUCTS, FOR CAUSING SAID COOLANT TO FLOW THROUGH SAID PASSAGEWAYS. 